Sunday, 19 January 2014

Michael McCullough bashes cultural evolution

Michael McCullough's 2014 Edge question piece was on Human Evolutionary Exceptionalism. He followed it up with a blog post on why human groups and human language don't represent "Major Evolutionary Transitions".

Here, I'll contrast my views with Michael's. Michael writes:

Humans' niche construction activities have undoubtedly exposed new covariances between genetic variation and fitness during human evolution, but those activities have neither created that variation nor filtered it, so they don't constitute an evolutionary process.

This is the fallacy that evolutionary processes must be based on DNA genes. Michael doesn't mention DNA - but it is clear that is essentially what he means. He's saying that cultural reproduction of books isn't really "genetic" - and so doesn't really evolve. This is a huge mistake - culture evolves. It has genes of its own, they are called memes. If there's a problem with "niche construction", it is its name - which confusingly classifies a lot of destructive activities as "construction".

On major transitions, Michael writes:

Their second category mistake was to hold up human language as the outcome of major evolutionary transition. To be sure, human language, as the only communication system with unlimited expressive potential that natural selection ever devised, is biologically exceptional. However, the information that language conveys is contained in our minds, not in our chromosomes. We don’t yet know precisely where or when human language evolved, but we can be reasonably confident about how it evolved: via the gene-by-gene design process called natural selection. No major evolutionary transition was involved.
Hang-on! Language evolved by a process of cultural evolution, in which words and syllables adapted themselves to the human mind. Yes, there might have been a little genetic change as a result - as genes adapted to their new culturally-constructed environment - resulting in "babbling babies" and explaining why chimpanzees learn language poorly. However, language is primarily a cultural phenomenon that evolved via cultural evolution. We can see languages evolving in real time, and we can see that their adaptations to their human hosts have precious little to go with changes in DNA genes - since languages evolve far too quickly.

It may still be a little bit early to classify this phenomenon as a "Major Transition" - since it is still going on. Memes have already had an enormous impact on the biosphere, but any "transition" is pretty clearly still "in progress" - and won't be complete until human brains have all been scanned into the matrix.

In his blog post, Michael seems to say that even this wouldn't count - since evolution only works on DNA genes, and humans uploading themselves in the matrix wouldn't make much difference to this - since bacteria would be unaffected (maybe). Maybe. He says:

Evolutionary transitions are about information stored in DNA, not about information in people’s minds.

However if 99% of the biomass on the planet becomes based on memes - rather than DNA genes - that would be a pretty major change - even if the remaining DNA transmission wasn't very much changed in the process. Michael's emphasis on DNA is a mistake - since what we are looking at is a memetic takeover in progress. See my Genes are not sections of nucleic-acid post for more on this whole topic.

Lastly we have this:

In the past, all of these cooperation-related phenomena spent time on evolutionary scientists' lists of "unsolved puzzles about human cooperation." The good news is that scientists have already succeeded in nudging many of them toward the "solved puzzles" list. The bad news is that some scholars have gone in the opposite direction: They have moved these problems onto the list of "mysteries"—problems so perplexing that we should abandon hope of ever solving them within the standard inclusive-fitness-maximizing view of natural selection. Their mystification has led them, at turns, to invoke evolutionary explanations that are inappropriate for species in which all individuals reproduce, to propose new evolutionary processes that are not evolutionary processes at all (but rather, proximate behavioral patterns that require evolutionary explanations), and to presume without justification that certain quirks of modern social life were selection pressures of our deep evolutionary past. Explaining the exceptional features of human cooperation is challenging enough without muddling the problem space even further with conceptual false starts, questionable historical premises, and labyrinthine evolutionary scenarios.

This is a full-throated critique of cultural evolution. Cultural evolution is a fact. Yes, it does involve some rather "labyrinthine evolutionary scenarios", but that's just how our species evolved. You can't reduce the complexity of the process by sticking your head in the sand and pretending that cultural evolution doesn't exist.

Remember, folks, that not much in human origins makes sense, except in the light of culutral evolution.

On the positive side, cultural evolution works a lot like the way in which organic evolution does. So, the symbiosis between memes and our brains is not so much different from the symbiosis between termites and their gut bacteria. We can understand human ultrasociality as the product of memes manipulating humans into frequent close contact to facilitate their reproduction, in much the same way that termites are manipulated by their gut bacteria into frequent close contact to help the bacteria reproduce. Similarly, humans use their memes to adapt to their spatio-temporally diverse environment, just as termites use bacterial evolution to adapt in real time to different food sources.

Nor are humans the only creatures with cumulative cultural evolution. Chimpanzees have it too, and so do whales. We are an exception - in that we have cumulative cultural evolution and an opposable thumb. Every species is different in some way. However, our difference does seem to be one that makes a difference.

Michael evidently didn't feel the paradigm shift yet. He directs the Evolution and Human Behavior Laboratory at the University of Miami. You can be that that is one place where the study of cultural evolution is being stifled.

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